Studies on the Resistance of the Peritoneal Mesothelium to Solute Transport

Open Access
Publisher Website
Google Scholar
Abstract
Permeability of the mesothelium for rubidium and albumin was evaluated in vitro. There were pores through which free diffusion of rubidium occurs in 0.03% of the mesothelium area. On the other hand, albumin seems to be transported through transport system by some mechanism other than simple diffusion. The role of the mesothelium as a barrier to the transport of solutes during peritoneal dialysis is not cleared finally (I). Most of the data characterising the transport characteristics of the peritoneal membrane were obtained from in vitro studies (2–4). From their in vitro studies Gosselin and Berndt calculated that, on the aggregate, water-filled pores, through which small molecules may diffuse, occupy 0.6% of the area of the mesentery (5). However we showed, recently, that the values of the transport rate of various substances across the mesentery in vitra are overestimated because of damage to the membrane edges (6). All the membranes studied in vitro are damaged as a result of compression between the edges of the chambers used for study. This damage creates an additional (shunt) pathway through which solutes can be transported at the same time as they cross the undamaged membrane. We decided to re-evaluate the calculations of Gosselin and Berndt, based on our studies of the bidirectional, transmesothelial transfer of rubidium (m. w. 86) and albumin, (m. w.X 68000) and correcting for the existence of the edge damage.